Twenty-one symptomatic subjects with
pigeon breeders' lung (PBL) and 10 asymptomatic pigeon breeders, with a similar exposure to pigeon
antigens, underwent bronchoalveolar lavage. Total
IgG,
IgM and
IgA in lavage fluid were determined as were specific antibody levels against
antigens in pigeon serum and droppings. Results were converted to levels in epithelial lining fluid (ELF) using lavage and serum
urea ratios. It was found that symptomatics represent a group that is hyperreactive to pigeon
antigens compared with the asymptomatic group with significantly higher
IgG,
IgM,
IgA levels as well as specific antibody levels against pigeon serum and droppings. Paired serum and ELF samples from 12 symptomatic subjects showed significantly elevated
IgG,
IgM and
IgA levels in ELF compared with serum when values were expressed in terms of
albumin. This strongly supports the concept of local production of
immunoglobulins within the lung after inhaling immunogens as opposed to their diffusion from the vasculature. Results for
IgA indicate that any putative protective role for this
immunoglobulin is not valid in relation to the prevention of
extrinsic allergic alveolitis. Analysis of smoking habits, lung
immunoglobulins and response to inhalation challenge confirm the negative influence of smoking on total and functional lung
immunoglobulins; however, levels in the ELF of ex-smokers suggest that the effect of smoking is not permanent. Smoking did not prevent responses to inhalation challenge.